aura: Make RootWindow::DispatchKeyEvent drop unknown keys.

ui/aura/root_window.h

Index: ui/aura/root_window.h
diff --git a/ui/aura/root_window.h b/ui/aura/root_window.h
index 43d1fc8b079dcb588220fce5839277075179f29a..66d7ba1d22ad3b2d1ce6a5564070c905a91f1aaa 100644
--- a/ui/aura/root_window.h
+++ b/ui/aura/root_window.h
@@ -248,11 +248,10 @@ class AURA_EXPORT RootWindow : public ui::CompositorDelegate,
   // Initializes the root window.
   void Init();
 
-  // We hold and aggregregate mouse drags as a way of throttling resizes
-  // when HoldMouseMoves() is called. The following methods are used to
-  // dispatch held and newly incoming mouse events, typically when an event
-  // other than a mouse drag needs dispatching or a matching ReleaseMouseMoves()
-  // is called.
+  // We hold and aggregate mouse drags as a way of throttling resizes when
+  // HoldMouseMoves() is called. The following methods are used to dispatch held
+  // and newly incoming mouse events, typically when an event other than a mouse
+  // drag needs dispatching or a matching ReleaseMouseMoves() is called.
   bool DispatchMouseEventImpl(MouseEvent* event);
   void DispatchHeldMouseMove();